“I just wanted to wish you a happy Doctor Who Day here, from Tom Baker,” the actor said in an official video. “I think of myself as the happiest of all the Doctor Whos. They [the other actors] might not agree with that, but then, pfft, let them disagree.”

Video of Happy Doctor Who Day From Tom Baker! - Doctor Who

The world was introduced to Doctor Who on Nov. 23, 1963, when the show materialized for the first time on the BBC with the first installment of “An Unearthly Child.” William Hartnell then starred as the First Doctor, a Time Lord from Gallifrey (although at the time he was introduced as a “mysterious exile from another world”) who traveled through time and space aboard a Big Blue Police Box with original companions Susan Foreman (Carole Ann Ford), the Doctor’s granddaughter, and school teachers Barabara Wright (Jacqueline Hill) and Ian Chesterton (William Russell) in tow.

Baker starred on the small screen as the much-loved Fourth Doctor from 1974 to 1981 and has reprised the role for the last five years in several Big Finish audio dramas. He also popped up in an uncredited cameo appearance during Doctor Who’s 50th anniversary special, “The Day of the Doctor” (2013), as a character named The Curator, and recently voiced the animated version of his Doctor for the lost Doctor Who episode "Shada."